Adlington set to defend 800m freestyle title

Britain's Rebecca Adlington swims to a first place finish in heat 5 of the women's 800m freestyle event during the London 2012 Olympic Games at the Aquatics Centre on Thursday August 2. (Reuters)

Rebecca Adlington, Britain's best hope of winning gold in London's Olympic pool, charged into the final of the women's 800 metres freestyle with the fastest qualifying time on Thursday.

Adlington, who ended Britain's long drought in swimming by winning two gold medals in Beijing four years ago, stayed on course to defend her 800 title.

She easily won her morning heat in a time of eight minutes, 21.78 seconds to go straight through to Friday night's final as the top seed.

"I'm going to give it my all in the final, it's all about who can get that finish," she told the BBC.

"During the next 36 hours, I'll have gentle swims. It's all about tomorrow night."

Denmark's Lotte Friis was second fastest, just 0.11 seconds behind Adlington. The pair have been racing each other since they were teenagers, taking turns at winning, with Friis winning the world title in 2009 and the European title last year.

"It was really easy and in control. I am satisfied with that race. Hopefully I will be even better than that tomorrow," she said.

"Rebecca Adlington is the main competition, she's the home crowd favourite and Olympic champion. I am not underestimating her in any way."

American teenager Katie Kedecky, the youngest member of the powerful U.S. swim team, was third quickest after suffering a bout of nerves before diving in.

"I had a lot of adrenalin. I might have kicked out a little fast," the 15-year-old said.

"This is my first international competition so to be at an Olympic Games is really great."

American Kate Ziegler broke down in tears when she missed out on the final after being struck down with influenza a few days ago that drained her energy.

"It's really bad timing, it couldn't be worse," she said.

"I was just going to do the best I could and this is what I could do."